There are certain diseases that are so difficult to treat that you definitely would want to have an immunity from them. Like cancer or type 2 diabetes. However, most of us are not protected from these conditions. Except people with a certain type of dwarfism. Now scientists from University of Queensland discovered why Laron dwarfs don’t get diabetes and rarely suffer from cancer.
People with certain types of dwarfism seem to be immune to type 2 diabetes and possibly even cancer. Image credit: Jan Fyt via Wikimedia
Laron syndrome is a type of dwarfism, caused by a mutant growth hormone receptor. As you probably understood already, Laron syndrome causes a short stature, but it doesn't stop there. People with this form of dwarfism have an increased sensitivity to insulin which means that they are less likely to develop type 2 diabetes and cancer. Scientists have never been completely sure what allows people with Laron syndrome to be so immune to diabetes and cancer. Understanding it could help us provide this immunity to other people as well. That is why scientists from Australia set out to solve this 50 year old puzzle.
People who suffer from Laron dwarfism a defective growth hormone receptor in their cells – this is pretty much the reason for their short stature. Defective hormone receptors make these people particularly sensitive to insulin (a hormone, regulating the metabolism of carbohydrates, fats and protein). Everyone has a different sensitivity to insulin and, probably, other hormones as well. Sensitivity for insulin decreases and the person puts on weight becoming obese. Eventually that is how some people get type 2 diabetes. However, people with Laron dwarfism seem to be disproportionally immune to these conditions. Scientists were puzzling over this issue for decades, but now they think that it has something to do with a signalling molecule activated by the growth hormone receptors.
This molecule, called STAT5, is responsible for regulating this insulin sensitivity. Since growth hormone receptors are faulty, STAT5 is not properly activated either. Dr Yash Chhabra, one of the researchers from the study, said: “This switching off of the STAT5 activation improved prevented insulin resistance by improving insulin signalling. This increased insulin receptors and reduced glucose output from the liver”. Now scientists are thinking about how to use this information to help other people who may be suffering from type 2 diabetes or cancer.
Researchers say that growth hormone receptors and STAT5 could become targets for new therapies. However, years will pass until they come. On the other hand, people with Laron dwarfism can be happy that they can at least avoid diabetes and have significantly lower chances of getting cancer.
Source: UCL